(1) Field of the Invention
The present invention relates to sealing assemblies used on rotating shafts and more particularly, relates to a compact floating seal system used on a drive shaft.
(2) Description of the Prior Art
O-ring seals are commonly used to seal rotating shafts used in vehicles or machinery. For example, in an existing torpedo tail cone assembly 10, FIG. 1, the drive shaft 12 of the torpedo is typically sealed with an O-ring seal system having a seal housing 14 and an O-ring seal 15 within a groove in an internal annular surface of the housing 14. The seal housing 14 is located within the tail cone housing 16 near the bearing 18. When the torpedoes have stable and concentric shaft bearing mounts relative to the seal, non-floating seal housings can be used, and these housings will still maintain reasonable clearance to prevent rubbing between the shaft 12 and the seal housing 14. Larger shafts that are mounted soft enough to move or float relative to the seal housing require floating seal housings. The floating seal housing moves with the drive shaft 12 generally in a radial direction as indicated by arrow 2 maintaining clearance of the shaft 12 and preventing the shaft 12 from rubbing against the seal housing 14.
In order to allow greater torpedo reliability and operations at depth, replacement of the prior art seal described above was proposed. The replacement seal must fit in the envelope occupied by the existing seal and seal on the same diameter shaft. Furthermore, the seal must be capable of supporting additional pressure at the rotational speed of the torpedo drive shaft.
Some methods for allowing greater reliability of dynamic O-ring seals include use of a lubricant recess and canting. A lubricant recess containing oil or another type of lubricant is provided between two O-rings. Canting (or slanting) the O-rings within the seal housing increases seal life by facilitating active lubrication of the seals as the shaft rotates. This technique improves the life span and capability of the seals by reducing the friction between the O-rings and the shaft.
One object of the present invention is a high pressure, dynamic seal system that minimizes the potential of rubbing and failure.
Another object of the present invention is the provision of a seal system that floats with the shaft at low pressures.
Yet another object of the present invention is a reliable high pressure seal system in which the sealing members are effectively lubricated.
A further object of the present invention is a high pressure seal system fitting that can be used in current systems.
Accordingly, the present invention provides a compact floating seal system for sealing a rotating shaft within a structure. The floating seal system has a cylindrical outer seal housing positioned within the structure with a cylindrical internal recessed region formed in the outer seal housing and a retaining flange extending into the internal recessed region. An axial retaining means axially retains the outer seal housing against the structure, and an outer torque member prevents rotation of the outer seal housing with respect to the structure. An inner seal housing is retained within the internal recessed region and abuts the retaining flange for preventing axial movement of the housing. The inner seal housing has a shaft aperture therethrough. First and second sealing member retaining grooves formed within the shaft aperture retain O-rings. A lubricant recess is formed within the shaft aperture between the grooves. A rotation prevention means allows radial deflection of the inner seal housing within the outer seal housing but prevents rotation of the inner seal housing with respect to the outer seal housing.